1. Field of the Invention
The present invention relates to an optical device for use in an optical communication system, a method of manufacturing the optical device, an optical communication component and an optical transmission apparatus.
2. Related Art of the Invention
In recent years, the optical fiber communication system has remarkably been developed, and has been applied and put into practical use in public communication, CATV, a computer network and the like. In the optical fiber communication system, there are used optical communication components for partially separating signals transmitted through optical fiber or attenuating signal strength.
There is, for example, an optical multiplexer/demultiplexer in the wavelength multi-optical transmission system for transmitting a multi-channel signal through one optical fiber cable. The optical multiplexer wavelength multiplexes signals of each channel from an optical transmitter through the use of optical signals having different wavelength to transmit to an optical receiver through one optical fiber cable. The optical receiver divides the optical signal having desired wavelength by an optical demultiplexer having a wavelength selecting function for demodulation. Further, there is an optical add/drop component for tapping only optical signals having specific wavelength, and on the other hand, allowing other optical signals to pass as they are.
FIGS. 7 and 8 are an external view and a structural cross-sectional view respectively showing one of conventional examples for the optical multiplexer, which is an optical communication component. A wavelength multi-signal from an input fiber 71 is collimated by a lens 83 and is incident on an optical filter 86 for separating signals. Light within a specific wavelength range is reflected or is allowed to pass therethrough by this optical filter 86, and those light is combined through lens 93 and 88 and is taken out at an output fiber 73 and an optical fiber 76. The optical fiber and the lens are fixed to a holder, and the optical filter and the optical axis are adjusted and are fixed by adhesion or welding.
In the structure of such a conventional optical communication component as described above, however, in order to minimize the combination loss, it is necessary to perform optical axis adjustment for the input fiber and output fiber through each lens with accuracy at micron level. For this reason, it takes time to adjust the assembly.
Also, after the optical axis adjustment, it is necessary to fix the holders 74 by adhesion through members, but misregistration may occur at the time of this fixing. Therefore, the yield is reduced.
Also, since the optical communication component manufactured as described above has been increased in cost, an optical communication transmission apparatus and system using the same would be increased in cost, and as a result, low-priced communication service has been difficult to be realized.
It is an object of the present invention to solve the above-described problems and to provide an optical device, optical communication components and optical communication transmission apparatus system easier to assemble, having simpler structure at lower manufacturing cost than the conventional example.
The 1st invention of the present invention is an optical device, comprising:
at least two first optical components;
a second optical component placed between said first optical components, or at an intersection point of optical axes to be formed by said first optical components; and
a placement member for placing said first optical component and said second optical component,
wherein said placement member has at least a groove portion for placing said first optical component, and
each portion of said first optical component and each portion of said groove portion have such a shape and size that optical axes to be formed by said first optical components are positioned within the same plane respectively in a state in which said first optical components are all placed on said groove portion.
The 2nd invention of the present invention is the optical device according to 1st invention, wherein optical axes of said first optical components are formed to become parallel said groove portion on which said first optical component is placed.
The 3rd invention of the present invention the optical device according to 1st invention, wherein said first optical components and an inner wall of said groove portion are at least in point-contact at least at two points at cross-sectional view direction of said groove portion.
The 4th invention of the present invention is the optical device according to 1st invention,
wherein a convex portion or a concave portion having a predetermined shape is formed at a position on said placement member whereat said second optical component is placed, and
on a base of said second optical component, there is formed a concave portion or a convex portion having a shape, which corresponds to said convex portion or concave portion having said predetermined shape of said placement member.
The 5th invention of the present invention is the optical device according to 4th invention, wherein said predetermined shape is any of shapes of a polygon pyramid, a cone, a polygon pillar, and a column or substantially hemispherical shape.
The 6th invention of the present invention is the optical device according to 4th invention, wherein said convex portion or concave portion having said predetermined shape is formed when each of said grooved portions is extended, and is intersected each other at a position whereat said second optical component is placed.
The 7th invention of the present invention is the optical device according to any one of 1st to 4th inventions, further comprising a clamping member for fixing said first optical components and said second optical component in cooperation with said placement member,
wherein said first optical components and said second optical component are fixed in such a manner as to be sandwiched between said clamping member and said placement member, and
said first optical component is fixed in a state where it can be freely inserted and removed.
The 8th invention of the present invention is the optical device according to any one of 1st to 4th inventions, further comprising a clamping member for fixing said first optical components and said second optical component in cooperation with said placement member,
wherein said first optical components and said second optical component are fixed in such a manner as to be sandwiched between said clamping member and said placement member,
an upper portion of said first optical components are exposed on a principal surface of said placement member other than said groove portion in a state where said first optical components are placed on said groove portion, and
said clamping member is fixed by contact with said exposed upper portion of said first optical components.
The 9th invention of the present invention is the optical device according to any one of 1st to 4th inventions, wherein said first optical components or said second optical component include at least a lens and/or an optical fiber.
The 10th invention of the present invention is the optical device according to any one of 1st to 4th inventions, wherein said first optical components or said second optical component include at least a ferrule provided at an end portion of said optical fiber.
The 11th invention of the present invention is the optical device according to 9th inventions, wherein within said groove portion, an end surface of said lens and an end surface of said optical fiber are in point-contact or plane-contact.
The 12th invention of the present invention is the optical device according to 9th invention, wherein a focus of said lens is positioned on an end surface of said optical fiber.
The 13th invention of the present invention is the optical device according to 12th invention, wherein said lens is a bi-convex or single convex cylindrical lens.
The 14th invention of the present invention is the optical device according to 12th invention, wherein said lens is a graded-index lens.
The 15th invention of the present invention is the optical device according to 12th invention, wherein said lens is a spherical lens having a refractive index of 2 or closest thereto.
The 16th invention of the present invention is an optical communication component using the optical device according to any one of 1st to 15th inventions, wherein said second optical component includes at least an optical functional device.
The 17th invention of the present invention is the optical communication component according to 16th invention, wherein said optical functional device has wavelength separating and/or combining functions.
The 18th invention of the present invention is the optical communication component according to 16th invention, wherein said optical functional device has polarization separating and/or synthesizing functions.
The 19th invention of the present invention is the optical communication component according to 16th invention, wherein said optical functional device has an optical attenuation function.
The 20th invention of the present invention is the optical communication component according to 16th invention, wherein said optical functional device has an optical isolator.
The 21st invention of the present invention is the optical communication component according to 16th invention, wherein said optical functional device has an optical circulator.
The 22nd invention of the present invention is the optical communication component according to 16th invention, wherein said optical functional device has an optical terminating function.
The 23rd invention of the present invention is the optical communication component according to 16th invention, wherein said optical functional device has an optical modulating function.
The 24th invention of the present invention is the optical communication component according to 16th invention, wherein said optical functional device has optical branching and/or synthesizing functions.
The 25th invention of the present invention is the optical communication component according to 16th invention, wherein said optical functional device has an optical switching function.
The 26th invention of the present invention is the optical communication component according to 14th invention, wherein said optical functional device has a light amplifying function.
The 27th invention of the present invention is the optical communication component according to 16th invention, wherein said optical functional device has a wavelength converting function.
The 28th invention of the present invention is the optical communication component according to 16th invention, wherein said optical functional device has a light emitting function.
The 29th invention of the present invention is the optical communication component according to 16th invention, wherein said optical functional device has a light receiving function.
The 30th invention of the present invention is the optical communication component according to 16th invention, wherein said optical functional device has a polarization converting function.
The 31st invention of the present invention is an optical transmission apparatus, comprising:
The optical communication component according to any of 16th to 30th inventions;
optical transmission means; and
optical receiving means,
wherein said optical transmission means and said optical receiving means are connected to each other through said optical communication component.
The 32nd invention of the present invention is a manufacturing method of an optical device having at least two first optical components; and a second optical component placed between said first optical components, or at an intersection point of optical axes to be formed by said first optical components, comprising the steps of:
forming a groove portion on a placement member body;
forming a placement portion on said placement member body;
placing and fixing said first optical components on said groove portion;
placing said second optical component on said placement portion;
adjusting said second optical component to set an optical path for said second optical component and said first optical components; and
fixing said second optical component adjusted.